Answer: Voltage-gated potassium channels open and some voltage-gated sodium channels inactivate. Potassium flows out of the cell
In neuroscience repolarization refers to the change in membrane potential that returns it to a negative value just after the depolarization phase of an action potential which has changed the membrane potential to a positive value. The repolarization phase usually returns the membrane potential back to the resting membrane potential. The efflux of potassium (K ) ions results in the falling phase of an …
In neuroscience repolarization refers to the change in membrane potential that returns it to a negative value just after the depolarization phase of an action potential which has changed the membrane potential to a positive value. The repolarization phase usually returns the membrane potential back to the resting membrane potential. The efflux of potassium (K ) ions results in the falling phase of an action potential. The ions pass through the selectivity filter of the K channel pore. Repolarization typically results from the movement of positively charged K ions out of the cell. The repolarization phase of an action potential initially results in hyperpolarization attainment of a membrane potential termed the afterhyperpolarization that is more negative than the resting potential. Repolarization usually takes several milliseconds. Repolarization is a stage of an action potential in which the cell experiences a decrease of voltage due to the efflux of potassium (K ) ions along its electrochemical gradient. This phase occurs after the cell reaches its highest voltage from depolarization. After repolarization the cell hyperpolarizes as it reaches resting membrane potential (−70 mV){in neuron −70 mV}. Sodium (Na ) and potassium ions inside and outside the cell are moved by a sodium potassium pump ensuring that electrochemical equilibrium remains unreached to allow the cell to maintain a state of resting membrane potential. In the graph of an action potential the hyper-polarization section looks like a downward dip that goes lower than the line of resting membrane potential. In this afterhyperpolarization (the downward dip) the cell sits at more negative potential than rest (about −80 mV) due to the slow inactivation of voltage gated K delayed rectifier channels which are the primary K channels associated with repolarization. At these low voltages all of the voltage gated K channels close and the cell returns to resting potential within a few milliseconds. A cell which is experiencing repolarization is said to be in its absolute refracto… Read more on Wikipedia
Blockages in repolarization can arise due to modifications of the voltage-gated K channels. This is demonstrated with selectively blocking voltage gated K channels with the antagonist tetraethylammonium (TEA). By blocking the channel repolarization is effectively stopped. Dendrotoxins are another example of a selective pharmacological blocker for voltage gated K channels. The lack of repolarization m…
Blockages in repolarization can arise due to modifications of the voltage-gated K channels. This is demonstrated with selectively blocking voltage gated K channels with the antagonist tetraethylammonium (TEA). By blocking the channel repolarization is effectively stopped. Dendrotoxins are another example of a selective pharmacological blocker for voltage gated K channels. The lack of repolarization means that neuron stays at a high voltage which slows sodium channel deinactivation to a point where there is not enough inwards Na current to depolarize and sus…